The point was to kill header bidding altogether forcing people onto google's exchange. Or some portion of the time, facebook's exchange. Basically Google and F

The point was to kill header bidding altogether forcing people onto google's exchange. Or some portion of the time, facebook's exchange. Basically Google and Facebook wanted to create a walled garden where you're more or less forced to bid on their ad exchanges. Since they control the ad exchange they can front-run everyone and bid using insider info. By eliminating all other competitors Google and FB can basically collude to split the pie.